Magazine inertia latch



March 17, 1959 c. H. MORSE MAGAZINE INERT IA LATCH 4 Sheets-Sheet 1 Filed Dec. 18, 1956 lNVENTOR CHARLES H. Mam:

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March 17, 1959 c. H. MORSE I MAGAZINE INERTIA LATCH "Filed Dec. 1a, 1956 4 Sheets-Sheet 5 INVENTOR. I 0040155 4 MORSE 6.2

. March 17, 1959 Filed Dec. 18, 1956 c. H. MORSE v MAGAZINE INERTIA LATCH 4 Sheets-Sheet 4 INVENTOR. v CHARL 5s H. M0852 MAGAZINE rNEnrr LATCH Charles Harry Morse, Herkimer, N. Y., assignor to Remngton Arms Company, Inc., Bridgeport, Conn., a corporation of Delaware Application December 18, 1956, Serial No. 629,146.

11 Claims. c1. 42-6) The-present invention relates to improvements in ate-ht repeating firearms, and more particularly tomechanisms whereby the inertia effects on cartridges in a tubular:

magazine may be controlled.

The invention is particularly adapted to autoloading or fore-end actuated firearms of the type having a tubularmagazine disposed below and generally parallel to-the firearm barrel from which cartridges are sequentiallyfed by a spring-pressed cartridge follower into a receiver on release of a magazine latch. In most firearms of this type, the magazine latch is released as an incident to the reciprocation of the breech bolt in the receiver (in the rearward movement thereof). On the release of the magazine latch, the rearmost cartridgein the magazine isforced from the magazine onto a cartridge carrier which at the'proper time in the cycle of breech bolt reciprocation is elevated and aligns the cartridge with the barrel chamber for insertion by the forward, closing motion of the breech bolt.

In firearms of this type, the action may be operated very rapidly to eject a spent cartridge and effect transfer of a fresh cartridge from the magazine into the barrel chamber. Because of the rapidity of such transfer and the consequent short period of time available to move a cartridge from the magazine tube onto the carrier, a relatively strong magazine spring is usedto insure rapid cartridge movement from the magazine tube.

Even when firearms of this type are equipped withmagazine springs of suflicient strength to normally transfer a cartridge to the carrier in the available time period, feeding malfunctions frequently occur when the action is operated during recoil of the firearm. It has been found that these malfunctions are caused by inertia effects on the cartridges or cartridge in the magazine tube which tend to hold the cartridge column stationary whilethe firearm recoils rearwardly. The inertia of' the cartridge column acts against the magazine spring'and cartridge follower, causing the spring to compress, thus permitting the cartridge column to be disposed forwardlyin the magazine tube away from the magazine latch. Unless the cartridge to be transferred from the magazine to the barrel chamber is in contact with the magazine latch atthe proper'time in the cycle of operations, feeding malfunctions will result. This inertia effect is most pronounced when a single cartridge is in the magazine and the magazine spring is only partly compressed, and is least pronounced when the magazine is full of cartridges and the magazine spring is strongly compressed.

The usual approach for solving the problem of shellmovement in the magazine tube during recoil of the firearm is to employ an extremely strong magazine spring to offset the inertia effects on the movable elements in the magazine tube. Very strong magazine springs present several disadvantages in use. Such springs makethe insertion of cartridges into the magazine difficult to acicomplish. Further, heavy magazine spring pressures loften force cartridgesagainst the magazinelatch with sufiicient force to interfere with proper functioning of the magazine latch. Still further, the available volume within the magazine tube limits the size of the magazine spring which can be utilized, and springs of requisite size and compressive strength to overcome inertia effects-give extreme variations in the force they exert, as the ber of cartridges in the magazine changes.

It is an object of this invention to provide mechanism for controlling the inertia efiect on cartridges in a tubular magazine.

Another object of this invention is to provide mechanism which will eliminate forward movement of a cartridge or cartridges in 'a tubular magazine when the firearm recoils. I

A further object of this invention is to provide mechanism which will permit the use of a light magazine spring. i i

A further object of my invention is to provide mechanism which will prevent displacement of a cartridge in the magazine from the magazine latch, and thus elimi'-' nate feeding malfunctions occasioned thereby.

It is contemplated that these objectives'may best be achieved by providing an inertia latch operated by the recoil of the firearm which will detent one or more ofclosed, the contemplated latch comprises a pivot ed mern-' her having its center of mass eccentric to its center of rotation, which member is disposed to engage between one of the movable elements in the magazine and a rigid portion of the firearm by inertia when the firearm recoils, thus detenting said movable element or elements from movement away from the shell latches as the firearm recoils.

It is emphasized that the embodiments of my inven-' tion to be disclosed are equally applicable to repeating firearms of all types having a tubular magazine coextensive, with a barrel wherein the action of the firearm may The so-called and rifles by the employment of my invention.

In the drawings: Figure 1 is a'fragmentary sectional side elevation of firearm incorporating one embodiment of my invention. Figure 2 is a plan view of the firearm of Figure l with part of the barrel broken away to show the invention.

Figure, 3 is a view similar to Figure 1, but showing the functioning of the invention when the firearm is discharged.

Figure 4 is a fragmentary sectional side elevation of a firearm having a second embodiment ofmy invention mounted in the magazine follower.

Figure 4a is a vertical sectional view on line 4a- -4a of Figure 4.

Figure 5 is a view similar to Figure 4, but showing the device of my invention in a different position in the firearm magazine.

Figure. 6 is a fragmentary sectional side elevation of a firearm incorporating another embodiment of my inven tion mounted on the magazine tube for engagement with a cartridge.

Figure 7 is a plan view of the embodiment of Figure 6 taken on line 77 of Figure 6.

Figure 8 is a fragmentary sectional side elevationofa firearm incorporating still another embodiment of my. in;

nu -i I a 3 vention disposed in the magazine follower for frictional engagement with a magazine tube.

Figure 9 is a view similar to Figure 8, showing the operation of 3 this embodiment when the firearm is di s rs a 9 Figure 10 is a transverse sectional view taken on line 10*-10 of Figure 9. i j L The repeating firearm herein chosen for illustration and description of my invention is a shotgun of the autoloading type disclosed in" the application of Lexie Ray. Crittendon, Serial No. 582,153, filed May '2, .1956. j

- Referring to the drawings, theillustrated shotgun com prises a receiver 1 on which is secured a barrel 2 having a barrel chamber 3. Below the barrel and coextensive therewith is a receivermounted magazine tube 4 having. one end in open communication with the receiver. Within the magazine tube, a spring 5 mounted against a forward abutment which is not shown, resiliently biases a reciprocable cartridge follower 6 toward receiver open ing 1a. A shell 7 is pressed into engagement with a magazine latch 8 at the receiver opening. A shell carrier 9 is disposed in the lower portion of the receiver and receives shells released from the magazine latch for transfer to the barrel chamber when the magazine latch is released at the proper time in the cycle of action operation. A full description of the operation of this shotgun may be had by reference to the aforementioned patent application. I i

Figures 1 to 3 showone embodiment of my invention wherein an inertia latching device is mounted on the magazine tube immediately forward of the position as: sumed by a cartridge follower in the magazine tube when one shell remains in the magazine. In this embodiment, the inertia latching device engages behind the rim of the cartridge follower when the firearm recoils, thus preventing forward displacement of the follower and the shell retained against the magazine latch by the follower.

A mounting block 10 fixed to the magazine tu-be 4 by brazing or other desired means comprises the spaced upstanding walls 11 joined through a portion of their length by the recessed web 12. A slot 13 generally co extensive with the unconnected portion between the upstanding walls provides communication to the interior of the magazine tube. m

An inertia-operated latch member 14 having limitedpivotal movement in a vertical plane is retained between the spaced walls by means of the pivot pin 15 which engages in a cut-out 16 formed in the top surface of the. latch member. A stop pin 17 extending between the spaced walls registers with a second cut-out 18 in the top,surface of the latch member and provides a limit stop for clockwise rotation of the latch member. A relatively weak compression spring 19 contained in a counterbore 20 in thelower surface of the latch member bears. against the surface of themagazine tube-and lightly urges the latch memberin a clockwise directionlinto contact with the stop pin, as shown in Figure 1. This is the normal position of rest of the latch member, audit will be seen that the latch member is wholly contained; between the upstanding walls and does not protrude into the magazine. Cartridges in the magazine tube and the cartridge follower can move freely in the magazine without obstruction by the latch member. I,

It will be noted that the latchmember is unbalanced. with respect to its center of rotation established by the pivot pin 15. Stated in another way, the center of mass of the latch member is eccentric to its center of rotation. Further, the latch member is disposed at a slight vertical angle to the normal plane of the firearm barrel. The unbalanced condition of the latch member and its angular position cause the latch member to rotate by inertia in a counter-clockwise direction about the pivotpin 15," overcoming spring 19, when the firearm recoils alongthe normal planeof the barrel. t The position which the latch member assumes by ing in curvature to the wall of the magazine tube.

inertia during recoil of the firearm is shown in Figure 3.

It will be seen that the lateh member has pivoted in a counter-clockwise direction about the pivot pin, and face 21 of the latch member is disposed behind the rim of the cartridge follower. The displacement of the latch member by inertia forces, occurs early in the recoil movement of the firearm, before the inertia of the cartridge follower and the cartridge overcomes the pressure of magazine spring 5. The cartridge follower is restrained from forward movement in the magazine tube by the latch element, and therefore assumes the rearward recoil movement of the firearm.

The cartridge is retained from forward displacement by the detented cartridge follower and therefore remains adjacent the shell latch, assuming the rearward movement of the firearm. The magazine spring 5 is subject to inertia forces as the firearm recoils, but such forces g by the nature of the spring, are inherently light, and the spring continues to exert a substantialproportion of its pressure on the cartridge follower.

If the action of the firearm is now operated while the firearm is in recoil, the magazine spring and cartridge follower will transfer the cartridge 7 to the cartridge carrier 9 almost instantly when the magazine latch is released. It will be seen that the inertia forces which might otherwise cause the cartridge to be out of position for feeding to the carrier have been controlled by the i use of myinvention.

It is obvious that the latch member will be returned to the described position of rest by the spring 19 when the rearward acceleration imparted to the firearm byrecoil subsides. p

When the device of my invention is used on a shot gun of the type described, it has been found that magazine spring pressures may be reduced by 50% with virr tual elimination of feeding malfunctions. Another embodiment of my invention is shown in 1 Figures 6 and 7 in which a pivotally mounted inertia member is disposed on a magazine tu=be adjacent the receiver opening thereof for detenting engagement behind the rim of a shell resting against the magazine latch when the firearm is in recoil. This embodiment is particularly adapted for use where only the shell at the magazine latch need be restrained from inertia movement during recoil, and variations in shell lengths make detenting of the magazine follower at a fixed point impractical.

The. inertia member of my invention is mounted adjacent the receiver opening 1a on the magazine tube. The upper surface of the magazine tube is cut outat 35 to receive the inertia member which is preferably formed from sheet stock and comprises a base section 36 conform- Upstandinglegs 37 are formed on the inertia member and have mounting holes 38 formed therein. A hollowed-out latch mounting block 39 straddles the rearward portion of the cutout in the magazine tube, and has forwardly extending section 36a provided with an axle pin 39 fixed therein, on which the inertia member is pivotally disposed in the cutout portion 35 of the magazine tube. The base section of the inertia member in the position of rest; shown in Figure 6 lies generally in this plane of the wall of the magazine tube and substantially fills the cutout portion; i

It will be noted that the inertia member is unbalanced with respect to its center of rotation, the base section being disposed below the axle pin, with the majority of the mass of the base section rearward of the axle pin.

The center of mass of the inertia member is thus eccentric to its pivotal mounting on the axle pin. A relatively weak paired torsion spring 40 is mounted, on the axle pin 39 with the open legs 41 of the spring extending within the hollowed out mounting block 39 and bearing againstllthe surface thereof. Theopposed. closed leg-42 of the spring bears against the base section of the inertia member and urges the inertia member in a clockwise direction to the position of rest shown. The spring 4t! normally maintains the inertia member in the positionof rest, but is of insufficient strength to prevent counterclockwise rotation of the inertia member by inertia forces generated by the recoil of the firearm when discharged. When the firearm recoils, the inertia member rotates in counterclockwise direction about pivot pin 39 until the slightly arcuate rearward edge 43 of the inertia member contacts the body of shell 7 immediately in front of the shell flange as shown in Figure 6. Rotation of the inertia member to this detent position takes place early in the cycle of recoil, before the inertia of the shell 7 overcomes the pressure of the magazine spring 5. Any relative movement of the shell 7 in the magazine tube 4 during recoil will be prevented by the engagement of the face 43 of the inertia member with the shell flange. The shell is thus maintained adjacent the magazine latch and the magazine spring is relieved of the inertia loads which would have been imposed if the shell wasnot def tented. If the magazine latch is now operated during recoil, the magazine spring will rapidly transfer shell 7 into the receiver of the firearm at the proper instant.

This embodiment of my invention is equally applicable to tubular magazine rifles using the so-called rimless cartridges by slightly modifying the engaging face 43 of the inertia member to engage in the extractor recess near the base of the cartridge. It is also within the contemplation of my invention to provide an inertia member of the type just described disposed for engagement with the body of a cartridge at any point where a diametral dimension changes, such as the shoulder found in many high power rifle cartridges.

A furtherembodiment of my invention is shown in Figures 4 and 5, in which an inertia operated latch mem: her is mounted within a tubular magazine follower in a tubular magazine tube, for sequential engagement with a plurality of spaced latching surfaces formed in the magazine tube, as successive cartridges or shells are fed from the magazine tube and discharged. This device is particularly adapted for use on tubular magazines of large cartridge or shell capacity where it is desirable to detent a cartridge column, at each discharge of the firearm;

With reference to the drawings, a firearm of the type disclosed in the aforementioned patent to Crittendon is shown, generally having a receiver 1, a barrel 2 attached thereto, having a barrel chamber 3 and a magazine tube 4, coextensive with the barrel and opening into the receiver at- 1a. Within the magazine tube, a hollow magazine follower 6 has provided thereon a cup-shaped element against which the magazine spring 5 bears. Within the magagine follower, as shown in Figures 4 and 4a, a

mounting block 22 is fixed to the interior wall by brazing of the latch by engaging an upper face 27 of the latch.

member. A relatively weak compression spring 28 disposed between the abutment 26 and a recess 29 formed in the upper face 27 of the latch member normally urges the latch member to the position of rest shown.

It will be noted that the latch member is angularlydis posed with respect to the longitudinal axis of the firearm along which recoil forces are exerted. Further, it will be seen that the greater mass of the latch member is disposed above the center of rotation established by the pin 23. The combination of these factors causes the latch member to rotate in a clockwise direction overcorn-.

6 ing spring 28, when subjected to inertia forces created by recoil of the firearm.

A plurality of cutouts 24 and 30 are spaced along the wall of the magazine tube in such placement that they align with the latch member in each position assumed by the follower as successive shells are fed from the magazine into the receiver. As shown in Figures 4 and '5 the latch member aligns with cutout 30 when two shells are in the magazine tube, and aligns with cutout 2.4 when only one shell is in the magazine tube. The forward edges of cutouts 24 and 30, respectively, form latching surfaces 31 and 32 which engage with a lower face 33 of the latch member when the firearm is in recoil.

The manner in which the latch member engages the latching surfaces will now be described. When the firearm is discharged the forces attendant on discharge of the chambered shell 7 cause the firearm to recoil to the left along its longitudinal axis. Inertia forces acting on the greater mass of the latch member above the pin 23 cause the latch member to rotate in a clockwise direction overcoming the relatively weak spring 23, bringing'the upper face 27 into engagement with the abutment 26; The elevated position that the latch member assumes during recoil is shown in dotted lines in Figures 4 and 5. Such rotation occurs very rapidly at the first imposition of recoil due to the relatively weak restraint placed on the unbalanced latch member by spring 28, and the latch member assumes the elevated position shown in dotted lines beforethe inertia of the shells 7 and 7' and the magazine follower overcome the restraining force of the magazine spring. When the latch member is at its, extent of clockwise rotation, the lower face 33 is opposed to the latching surface 31 or 32, as the case may be. Forward displacement or the magazine follower within the magazine tube is thus prevented by the interengagement of the lower face of the latch member with the latching surface of the magazine tube, and the magazine follower and shells are compelled to assume the recoil movement of the firearm.

The magazine spring is relieved of the function of overcoming heavy inertia forces, and shell 7 is main? tained adjacent the shell latch 8 during recoil. If shell latch 8 is opened by operation of the action during recoil, shell 7 or 7" will be immediately transferred into the receiver by the force of the magazine spring. It will be noted that the latch member is only effective to prevent forward movement, away from the receiver, of the follower and shells during recoil, and presents no obstruction to movement of the follower in feeding shells to the receiver. If the latch member is in elevated position when the follower moves to transfer a shell to the receiver, the curved reverse face 35 of the lower portionof the latch member will strike the edge of the cutout in leftward movement of the follower, causing the latch y member to pivot in a counter-clockwise direction to its position of rest.

The relatively weak spring is provided to insure that the latch member fully enters its position of rest when not subjected to recoil forces. When in the position of the rest shown, the latch member presents no obstruction to movement of the follower. and loading of shells may be easily accomplished.

It will be seen that this embodiment of my invention prevents forward displacement of the shell column and the magazine follower during recoil regardless of the number of cartridges in the magazine tube. Where tubular magazines having a capacity of three or more cartridges are used, the inertia forces tending to displace the cartridge column are of great magnitude, and the long magazine springs which are necessary in such magazines have compression pressure characteristics which are highly variable depending on the number of cartridges in the magazine. By detenting the cartridge column and the magazine follower from displacement during each recoil of the firearm, I eliminate feeding difficulties arising' from such movement; Further, a magazine spring of much less compressive strength may be employed.

Still another embodiment of my invention is shown in Figures 8, 9 and 10, in which an inertia operated member mounted in a magazine follower engages with a wall of the magazine tube during recoil to force the magazine follower into frictional detenting engagement with the magazine tube inner surface. This, embodiment is particularly adapted for use on tubular magazines of large cartridge capacity where variations in cartridge or shell lengths make it impractical to detent the magazine follower at predetermined points of movement.

In Figures 8, 9. and 10 is shown a shotgun of the type previously described comprising areceiver 1, a forwardly extending barrel 2, and a magazine tube 4 coextensive with the barrel. Within the magazine tube, shell 7 is urged against shell latch 8 at the rearward received opening 1:: of the magazine tube ,by magazine spring acting on a cup-shaped element 6a disposed in the mouth of the hollow magazine follower 6. The magazine follower is of such circumferential dimension as to be normally reciprocable within the magazine tube for loading shells into the magazine and transferring loaded shells into the receiver in the operation of the firearm. At the lower side of the magazine follower, a longitudinal slot 44 is formed in the wall of the magazine follower. Within the hollow magazine follower and straddling the slot 44 a mounting block is disposed having spaced walls 45. An axle pin 46 extends between the spaced walls 45 and supports an inertia member 47 for pivotal movement in a vertical plane in alignment with the slot 44. i

The inertia member 47 is generally kidney-shaped and is formed of a heavy metal such as brass or steel. The bulbous upper portion of the inertia member disposes the majority of the mass of the member above the pivotal center defined by the axle pin 46. Below the axle pin, a camming surface 48 is formed on the inertia member. The camming surface is of such curvature that clockwise rotation of the inertia member during recoil will cause the camming surface to project through slot 44 and engage the wall of the magazine tube as will be hereinafter described. A moderately hard friction material 49 such as asbestos or cork compositiomor the like, is fixed on the camming surface 48 by bonding or other means, and provides for positive non-slip engagement between the camming surface and the magazine tube during recoil.

A flat spring 50 having one end fixed to the mounting block, and the free end engaged with the inertia member, normally urges the inertia member in a counterclockwise direction to the position shown in Figure 8,. in which the upper portion 47a rests against the vertical wall of the magazine follower. It will be noted that in the position of rest shown, the inertia member is not in contact with the wall of the magazine tube, and the follower has adequate clearance to reciprocate within the tube during loading operations and shell feeding operations.

The operation of this embodiment of my invention will now be described. When the firearm is discharged, it will recoil rearwardly to the left. Inertia forces acting on the greater mass of the upper portion 47a of the inertia member 47 will cause the inertia member to pivot in a clockwise direction about the axle pin 46,. overcoming spring 50 and forcing the camming surface 48 into engagement with the inner wall of the magazine tube 4. As shown in Figure 9 the engagement of the camming surface 48 with the wall of the magazine tube enforces a vertical component of movement on the magazine follower, which causes it to rise in the magazine tube bringing the upper surface 51 of the follower into engagement with the inner wall of the. magazine tube at 52. The frictional engagement of the magazine follower with the magazine tube is suflicient to prevent the forcesof inertia imposed on the shell S and themagazine jfollower during recoil from moving the follower relatively forward in the magazine tube against, the pressure of jmagazinespring 5, and the magazine follower and shells thus assume the rearward recoil movement of thefirearm to the left. m If the action of the firearm is now operated while the firearm is in recoil, and shell latch 8 opens, the magazine spring 5 will force the magazine follower rearward, camming the inertia member out of engagement with the wall of the magazine tube. The upper, surface of the magazine follower will thus be released from frictional engagement with the wall of the. magazine tube a'nd the magazine followerwill be free to move rearwardly and transfer shell S into the receiver. Q {X The forces of inertia act on the inertia member dur ing the first stages of recoil, forcing the magazine fol; lower into frictional engagementwith the magazinetube wall'before the inertia forces acting on the shell and magazine follower overcome the pressure of the maga zine spring. p

The frictional material 49 on the camming surface 48 provides a non-slip engagement of the inertia mem-, her ,with the magazine tube wall. Any tendency of the magazine follower to move forward in the recoiling magazine tube will cause further clockwise rotation of the inertia member, due to its non-slip engagement with t the magazine tube wall, and such further rotation will increase the frictional engagement between the follower and the magazine tube. y j When the detented magazine follower assumes th rearward movement of the recoiling firearm, forcesact- I ing on-"the inertia member are substantially diminished,

andj'theforce of the magazine spring will be sufficient to'rotate the inertia member out of engagement. .The urging'of spring 50 assists in the disengagement offt he inertia member and maintains the member in the position of rest during shell loading and feeding operations. It will be seen that this embodiment of my device is adaptable to any tubular magazine firearm wherein mag azine tube dimensions are sufticient to permit a suitable inertia'member to be installed in the magazine follower. This device may be used advantageously in any tubular magazine firearm having an action operable while the firearm is in recoil.

What is claimed is: p 1.'A firearm having a receiver, a barrel extending" from said receiver, a magazine tube coextensive with said barrel and communicating with said receiver, and reciprocable elements in said magazine tube including a magazine follower and at least one cartridge or. shell; the invention comprising means for restraining at' least one of'said reciprocable elements from inertial displace ment during' firearm recoil, said means comprisingaf latch member mounted to engage one of said reciprocable elements with said magazine tube on pivotal movement, said latch member being pivotally movableto' engaged position by inertial forces on recoil of said fire? arm. 3

2 A firearm according to claim 1, comprising spring, meansnormally biasing said latch member to a di sconnected position. i

3. A firearm according to claim 2, in which said latch member is pivotally mounted on said magazine tube for.

connecting. engagement with said magazine follower 4. A firearm according to claim 2, in which said latch member pivotally mounted on said magazine tube for connecting engagement with said cartridge or shell.

5. A firearm according to claim 2, in which said latch; membenis disposed in said magazine follower element for pivotal engagement with the wall of said magazine tube.

a firearm having a receiver, a barrel extending from said receiver, a magazine tube element coextensive may with said barrel and communicating with said receiver, and a magazine follower element normally reciprocable in said magazine tube element, the invention comprising inertia operated detent means mounted on one said element for engagement with the other said element by forces of firearm recoil to thereby restrain said cartridge follower element from inertial displacement during firearm recoil.

7. A firearm comprising a receiver, a barrel extending from said receiver, a magazine tube mounted coextensive with said barrel and in communication with said receiver, reciprocable elements in said magazine tube including a column of cartridges and a magazine follower, a magazine spring urging said reciprocable elements toward said receiver, a firearm action including cartridge stop means in said receiver adapted to release cartridges one at a time from said magazine tube when said action is operated, and means for restraining said reciprocable elements from inertial displacement during firearm recoil, said means comprising an inertia operated latch member pivotally mounted in said magazine follower, and longitudinally spaced latching surfaces on said magazine tube, said latching surfaces being disposed to be successively engaged by said latch member during successive firings of the firearm.

8. In a firearm of the type having a barrel and a coextensive magazine tube mounted in communication with a common receiver, cartridge feed means in said magazine tube comprising a spring biased magazine follower, and action mechanism operable during firearm recoil to transfer a cartridge from said magazine tube to said barrel; the invention consisting of means to restrain said magazine follower from inertial displacement during firearm recoil, said means comprising in combination an unbalanced detent member mounted in said magazine follower for inertial rotation by firearm recoil, a cam sur- 10 face on said member disposed to frictionally engage said wall of said magazine tube when the member is rotated, and spring means normally maintaining said member in a disengaged position.

9. In a firearm having a receiver, a barrel extending from said receiver, a magazine tube coextensive with said barrel and communicating with said receiver, reciprocable elements in said magazine tube including at least one cartridge or shell and a magazine follower, spring means biasing said reciprocable elements toward said receiver, and action mechanism operable during recoil of the firearm to release a shell or cartridge for entry into said receiver, the improvement consisting of means for restraining at least one of said reciprocable elements from inertial displacement during firearm recoil, said restraining means comprising a latch member mounted on said magazine tube and inertially movable into engagement with one of said reciprocable elements by recoil forces.

10. The improvement set forth in claim 9, comprising spring means normally maintaining said latch member in disengaged position.

11. The improvement set forth in claim 9, comprising a latch mounting block disposed on said magazine tube, an elongate latch member pivotally supported by said block with its center of mass eccentric to said pivotal mounting, and a compression spring mounted between said latch member and said mounting block to bias said latch member to disengaged position.

References Cited in the file of this patent UNITED STATES PATENTS 228,778 Pease June 15, 1880 238,988 Tiesing Mar. 15, 1881 1,110,702 McClure Sept. 15, 1914 1,435,282 Declaye Nov. 14, 1922 

